Glossary

This glossary defines the key concepts behind DNS to help you understand how DNS works and what is meant in the documentation when certain terms are used.

A record

A records, or address records, assign an IPv4 address to a domain name.

AAAA record

AAAA records, or Quad-A records, associate an IPv6 address with a domain name.

CAA Record

CAA records, or Certificate Authority Authorisation records, provide additional verification for certificate authorities (CAs) to validate or issue SSL certificates for a domain.

CIDR notation

Classless Inter-Domain Routing notation, or CIDR notation, is a method of representing an IP address range on a network.

CNAME record

CNAME records, or canonical name records, associate an alias with a canonical domain name.

DNS Management

Domain Name System management, or DNS management, involves managing DNS records for a specific domain or a group of domains. For example, you can add an A record to a domain name such as example.com, which points the domain to the IP address of a ccloud³ VM. This means that every time a user types example.com into their browser, the browser connects to the IP address of the ccloud³ VM and displays all the websites hosted there.

DNS query

A DNS query is a request for information from a DNS server.

DNS record

DNS records, or Domain Name System records, map domain names to IP addresses and other information. Common types of DNS records include A records, AAAA records, MX records and NS records.

DNS server

A DNS server, also known as a DNS resolver, is a server that contains a database of public DNS records and associated hostnames.

IP

The Internet Protocol (IP) is a communication protocol used to connect computers via a network, in particular the Internet. IP consists of rules and regulations governing the transmission of packets over a network, including routing and addressing. IP ensures that the data packets travelling across a network reach their correct destination.

MX record

MX records, or Mail Exchange records, specify the mail servers responsible for receiving email on behalf of a domain.

NS record

NS records, or name server records, define which authoritative name servers contain the DNS records for a domain.

PTR record

PTR records, or pointer records (also known as reverse DNS or rDNS records), associate a domain name with an IP address. PTR records are used for reverse DNS lookups.

SRV record

SRV records, or service records, define the location (host and port) of specific services on a server. Some services, such as SIP and XMPP/Jabber, require SRV records.

SSL certificate

An SSL certificate is a digital document that verifies the identity of a website.

Tag

Tags are keywords associated with resources that help manage resource ownership and Support the organisation of search queries and actions relating to resources.

TLS (Transport Layer Security):

Transport Layer Security (TLS) is a security protocol that focuses on privacy and data security in internet communications.

TTL (Time to Live):

TTL, also known as lifetime or hop limit, is the period of time (also referred to as hops) during which a data packet exists before it is discarded by a router. TTL limits the lifetime of data in a network by setting a time limit on the data.

TXT Record (Text Record):

TXT records, or text records, define text information about sources outside a domain. Common uses for TXT records include creating email security records (DKIM and SPF records) and providing additional information about a domain.

Wildcard Record:

Wildcard records are DNS records that forward requests for non-existent subdomains to a specified resource or IP address.